Conventionally, when one uses a changer such as an auto tool changer (ATC) attached to the distal end of the wrist of a robot to perform multiple different operations while changing the hand with multiple hands, he/she needs to check whether the hand attached is suitable for each operation or not each time it happens. As a method for identifying whether a mounted hand is correct or not, an identification method using a camera is known (for example, see PTL 1). Furthermore, installing many sensors for hand identification on a hand stand is also conceivable.